Heretofore, the SMPTE (Society of Motion Picture and Television Engineers: Society of Motion Picture and Television Engineers) and the EBU (European Broadcasting Union: European Broadcasting Union) have examined the exchange of programs between broadcasting stations, and have then announced “EBU/SMPTE Task Force for Harmonized Standards for the Exchange of Programme Material as Bit streams” as the results of such examination.
In this announcement, essential data of a program, e.g. video and audio materials may be set to essence data (Essence), and contents of essence data, e.g. information such as a program title or a video system (NTSC or PAL) and an audio sampling frequency may be set to metadata (Metadata).
Next, essence data and metadata may constitute a content element (Content Element). Further, video and content items (Content Item) may be generated by using a plurality of content elements. For example, a video clip which may be useful as an index of images may be equivalent to this content item. Also, a plurality of content items and a plurality of content elements may constitute a content package (Content Package). This content package may be equivalent to one program, and a set of content packages is what might be called a wrapper (Wrapper). It has been proposed to make the program exchange become easy by standardizing means for transmitting this wrapper and means for accumulating this wrapper between the broadcasting stations.
The above-mentioned announcement has described only the concept of the program exchange, and has not yet concretely determined the manner in which a program can be transmitted. For this reason, the program could not be transmitted as the content package in actual practice in the above-mentioned manner.
Therefore, it is an object of this invention to provide a digital data transmission method in which a program can be transmitted in the form of a content package and a program transmission apparatus using such digital transmission method.